This invention relates to a method of preshaping and installing plastic tops for automotive vehicles. Passenger cars having plastic roof-top surfaces have become popular because of the potential for decorative effects, ease in keeping the surface clean and the long life of such surfaces.
For the most part, cars and other vehicles have sheet steel roofs, a substantial number of which are partly or completely covered with a layer of suitable plastic, as vinyl. The manner in which such plastic material is applied involves applying cement or adhesive to the surfaces of the metal roof top of a car and the inner surface of the plastic roof top material. A crew applies the precemented roof top plastic blank to the precemented car roof and adjusts the position thereof, conforming the shape of the plastic material to the car body by main force before the cement has set. Due to the fact that the roof top and some of the side portions of the car do not lie in a flat plane and due to the precut nature of the blank, it is necessary that the plastic blank be accurately positioned during the initial application of the roof top material to the car roof. It is necessary that wrinkles in the roof top material be avoided and that the shaped edges be accurately located in regions where decorative moulding is to be applied. During such an operation, considerable force is necessary in adjusting the roof top material because the cement prevents free movement between the roof top material and the metal of the car body. In addition, it is important that the outer surface finish of the plastic coating material be free from unsightly cracks, stains and wrinkles.
The application of the roof top material to the roof of a car generally occurs on a car assembly line where an automobile is assembled to end up in a completely finished car ready to be driven away. The inherent nature of this mode of applying a plastic top material to the roof of an automobile necessarily requires a fully manned crew of personnel and if the assembly line moves at the rate generally prevailing, would more frequently require a number of successive crews along the assembly line for handling the work where a large number of vinyl topped cars are involved. Apart from this, many vinyl tops will require some minor treatment to clean up the wear and tear of the vinyl surface during the trip of the car along the assembly line to the final inspection.